Nowadays, most widely used methods for hydrocarbon oil detection are based on methods using capacitive properties, photoluminescence with conventional detection (without photon counting), subsea images, satellite-processed images, conventional spectroscopy, module or derivative of the electromagnetic field and acoustic sensing.
A few of these well-known methods are the object of the U.S. patent documents U.S. Pat. Nos. 4,282,487, 9,217,317, 9,146,225, 9,052,276, 8,916,816, 8,445,841, 9,244,051, 9,222,892, 9,298,193, 8,030,934, US 20150285060, US 20150241296, US 20150192488, US20140303895, US 20140288853, US 20140284465, US 20140256055, US 20120059585, US 20120038362 and US 20090014325.
State-of-the-art technique for use in hydrocarbon oil detection resulting from oil spills are discussed in the paper by M. N. Jha, J. Levy et al “Advances in Remote Sensing for Oil Spill Disaster Management: State-of-the-Art Sensors Technology for Oil Spill Surveillance” Sensors. January, 2008, n° 8, pages 236-255.
The paper Oil Spill Detection by Satellite Remote Sensing by C. Brekke and A. H. S. Solberg, of March, 2005 pages 1-13 in “Remote Sensing of Environment” reports different automatic and manual approaches for using satellite sensors for oil spill detection.
One of the most commonly used techniques for hydrocarbon oil detection in the sea is by photoluminescence. This technique is being used for a long time for detecting oil spills on the sea surface and more recently, for detecting the presence of hydrocarbon oil in mixtures with seawater at great depths. However, the maximum distance between sensor and oil spills is very limited because of the low sensitivity of the photo detectors used and to the power limitation of the light sources.
Besides the reasons cited above, low detection sensitivities render prohibitive the use of optical fibers throughout long distances because of the high attenuation of these fibers in the visible spectrum wavelengths of petroleum oil fluorescence, that is, in the neighborhood of 500 nm.
One of the ways of identifying a molecule of a certain material is by Raman spectrometry, wherein a small fraction of the incident light on the material to be characterized is inelastically scattered at a frequency that differs from that of the incident light. Such variation in frequency, which occurs independently of the frequency of the emitted light, enables one to obtain information on the intrinsic characteristics of the molecule of the material to be analyzed. However, as the fraction of inelastically scattered light is very small, the detection of such light is extremely difficult.
Thus, the technique is still in need of a technical solution which could enable the efficient detection of photoluminescent particles (for example, petroleum oil) even when there is a significant distance between the detector and the particle.